It’s hard to go wrong with a Watergate special, and despite some debatable elements — beginning with the title — “All the President’s Men Revisited” holds true to form. Somewhat diluted in its split focus on Richard Nixon’s presidential malfeasance and the movie devoted to those acts, the two-hour doc doesn’t break much new ground, but does pore over familiar terrain, and its lingering implications, in an entertaining way. Produced by Robert Redford, what should have been “Watergate Revisited” nevertheless captures a period that remains deeply etched in the public consciousness, as the doc makes clear, for good and ill.

Loosely tied to the 40th anniversary of the year Washington Post reporters Bob Woodward and Carl Bernstein won the Pulitzer for their coverage of the break-in and cover-up (the movie actually came three years later), the doc features two sort-of reunions: Redford sitting with real-life alter ego Woodward, Bernstein and editor Ben Bradlee; and chatting with co-star Dustin Hoffman, dropping tidbits like how they memorized both sets of lines so the characters could literally finish each other’s sentences.

What really stands out, though, is unguarded footage of President Nixon as he prepares to deliver his resignation speech — seeking to banter playfully with those around him, yet simultaneously telling photographers that will be quite enough photos, thanks. In a way, those fleeting outtakes offer as much insight into the man as anything the various talking heads (including former speechwriter Ben Stein, who offers a full-throated defense) can muster.

Granted, that’s clearly a minority opinion, and with the benefit of hindsight, Bernstein says regarding the abuse of presidential power, “Nixon was worse than we thought.”

Watergate had profound implications for politics, the presidency and the relationship between politicians and the media, and that comes through loud and clear. There’s also a fascinating section on W. Mark Felt, the former FBI official revealed to be Deep Throat a few years before his death in 2008; and the importance of that character in transforming what might otherwise have been a rather dry look at journalistic legwork into a movie thriller — all while providing its own enticing, long-running real-life mystery. (There’s footage of a younger Felt steadfastly denying any role.)

Woodward talks somewhat wistfully about the luxury of having a “big fat institution” like the Post in its heyday to support the kind of investigative reporting “All the President’s Men” popularized, which takes on additional resonance given the downsizing of newspapers in recent years.

In his infamous secret Oval Office recordings, Nixon and top aide H.R. Haldeman actually laugh over how the sheer ineptitude of the Watergate affair might be their best shield against anyone thinking the White House was involved. “It would make a funny goddamn movie,” Haldeman says.

Actually, it wound up making perhaps the best movie that conveys the hard work of journalism. And with a few disclaimers, it makes for a special well worth visiting — and revisiting.

 All the President’s Men Revisited

(Documentary; Discovery Channel, Sun. April 21, 8 p.m.)

Produced by Partisan Pictures in association with Sundance Prods. Executive producers, Robert Redford, Andrew Lack, Laura Michalchyshyn; producer/director, Peter Schnall; camera, Schnall; writers, Chana Gazit, Patrick Prentice; music, Nathan Halpern. 120 MIN.